System safety principles: A multidisciplinary engineering perspective

System safety is of particular importance for many industries. Broadly speaking, it refers to the state or objective of striving to sustainably ensure accident prevention through actions on multiple safety levers (technical, organizational, and regulatory). While complementary to risk analysis, it is distinct in one important way: risk analysis is anticipatory rationality examining the possibility of adverse events (or accident scenarios), and the tools of risk analysis support and in some cases quantify various aspects of this analysis effort. The end-objective of risk analysis is to help identify and prioritize risks, inform risk management, and support risk communication. These tools however do not provide design or operational guidelines and principles for eliminating or mitigating risks. Such considerations fall within the purview of system safety.In this work, we propose a set of five safety principles, which are domain-independent, technologically agnostic, and broadly applicable across industries. While there is a proliferation of detailed safety measures (tactics) in specific areas and industries, a synthesis of high-level safety principles or strategies that are independent of any particular instantiation, and from which specific safety measures can be derived or related to, has pedagogical value and fulfills an important role in safety training and education. Such synthesis effort also supports creativity and technical ingenuity in the workforce for deriving specific safety measures, and for implementing these principles and handling specific local or new risks. Our set of safety principles includes: (1) the fail-safe principle; (2) the safety margins principle; (3) the un-graduated response principle (under which we subsume the traditional “inherently safe design” principle); (4) the defense-in-depth principle; and (5) the observability-in-depth principle. We carefully examine each principle and provide examples that illustrate their use and implementation. We relate these principles to the notions of hazard level, accident sequence, and conditional probabilities of further hazard escalation or advancement of an accident sequence. These principles are a useful addition to the intellectual toolkit of engineers, decision-makers, and anyone interested in safety issues, and they provide helpful guidelines during system design and risk management efforts.     

Corrosion behavior of steels for CO2 injection

The process chain for Carbon Capture and Sequestration (CCS) includes tubing for injection of CO₂ into saline aquifers. The compressed CO₂ is likely to contain specific impurities; small concentrations of SO₂ and NO₂ in combination with oxygen and humidity are most harmful. In addition, CO₂ saturated brine is supposed to rise in the well when the injection process is interrupted. The material selection has to ensure that neither CO₂ nor brine or a combination of both will leak out of the inner tubing. In this comprehensive paper the investigated materials range from low-alloy steels and 13% Cr steels up to high-alloy materials. Electrochemical tests as well as long term exposure tests were performed in CO₂, in brine and combination of both; pressure was up to 100 bar, temperature up to 60 °C. Whereas the CO₂ stream itself can be handled using low alloy steels, combinations of CO₂ and brine require more resistant materials to control the strong tendency to pitting corrosion. The corrosion behavior of heat-treated steels depends on factors such as microstructure and carbon content. For different sections of the injection tube, appropriate materials should be used to guarantee safety and consider cost effectiveness.     

"环境学导论"课的教学实践和思考

作为环境科学专业开出的第一门专业课程——“环境学导论”．其教学效果直接影响学生对所学专业的兴趣。笔者通过多年的“环境学导论”课的教学实践,从教材选择、教学过程、教学内容及教学方式、鼓励学生课外参与环境保护志愿活动方面提出了一点实践心得,也对教学实践进行了反思。     

事故的共性原因及其行为科学预防策略

任何事故都是有原因的,事故的原因可分为人和物两个方面,事故的严重度与事故频率间存在三角形分布规律.运用这三条安全科学基本原理和案例分析方法,分析多起不同类型事故.结果表明,事故的共性直接原因是安全知识、安全意识和安全习惯所引起的组织成员个体的不安全行为和物的不安全状态.用行为科学方法和系统化安全管理理论,制订了一个由规范组织成员个体安全行为的安全管理方案、个人行为纠正方法和安全培训组成的通用事故预防路线图,并阐述了路线图实施时所需要的组织行为分析、个人行为纠正和安全培训方法研究的最新进展.     

武汉市某区域大气颗粒物的测定与分析

采用电感耦合等离子体原子发射光谱法对TSP环境样品和尘源样品中的S、Si、Ti、Al、As、Ca、Pb、V等30余个元素组份进行分析并计算出各元素的含量,得到本区域大气环境TSP和污染尘源元素特征谱,并通过比较微波消解与加热消解两种方法的优劣,确定出较适应消解方法.结果表明,该区域中的A区污染源主要来自道路交通尘源和土壤尘源,B区污染源来自土壤尘源和建筑尘源.     

高含沙体系中影响硝基氯苯迁移转化因素的研究

通过静态吸附实验,研究了去除腐殖质的黄河泥沙对硝基氯苯的吸附规律及机理.实验结果表明,灼烧后的泥沙对硝基氯苯的吸附量随着平衡质量浓度的增加而增高,随粒径的减少而降低.含沙量100 g/L条件下,泥沙中的矿物成分的吸附占总吸附量的71%～82%;腐殖质吸附量占总吸附量的18%～29%.灼烧后的泥沙对硝基氯苯的吸附量随pH值变化较大,pH在6.66左右时吸附量最高.金属离子的存在使吸附量增加,不同金属离子的存在引起吸附量变化的程度不同.     

影响中国碳排放绩效的区域特征研究——基于熵值法的聚类分析

论文选择影响碳排放绩效的主要指标,基于熵值法确定各指标权重,采用系统聚类分析的方法,以中国省域为研究对象,将全国分为7类区域。分析结果显示:区域分工特征是造成目前中国省级碳排放绩效区域差异的主要影响因素,其次是高碳产业工艺特征和能源结构特征,而经济结构对解释省级碳排放绩效区域差异的贡献有限。北方地区高碳产品生产份额高且工艺水平相对低,能源消费中极高的煤炭比例加重了负面影响,造成其二氧化碳排放绩效水平低,特别是华北地区;近年来东南沿海地区高碳产业也逐步增加,但由于其工艺先进,在一定程度上抵消了高碳产品份额高的负面影响;中西部地区目前高碳产品份额虽然低于东部地区,但工艺水平也低,造成了其低水平的二氧化碳排放绩效。由于各省历史发展、自然资源禀赋、区域分工角色等因素不同,且遵从经济宏观发展客观规律和经济区位理论,除了少数发达地区之外,中国其他区域短时间内很难改变其经济和能源结构,低碳政策制定的重点应放在提高高碳产业工艺水平方面。     

Flash flood mitigation: recommendations for research and applications

Abstract

New technologies promise reduced flash flood losses. However, real-time observations with vast multi-sensor networks, more precise mapping capabilities using remote sensing and GIS, quicker hydrological and meteorological models, and increasing forecast lead times have not reduced losses. In November, 1999, 35 researchers from nine countries met in Ravello, Italy at a NATO sponsored Advanced Study Institute, to discuss these issues and to develop a research agenda that incorporates the various components required to cope with flash floods. The key recommendations from the Institute were: (1) greater emphasis on increasing understanding of the social processes involved in flash flood warning, particularly in the response phases, and (2) the need to reduce vulnerability in sustainable ways compatible with long-term economic and social goals. The relationship between hydrometeorology and social science is seen as critical to advancing our abilities to cope with flash floods.     

Challenges to interdisciplinary research in ecosystem-based management

Despite its necessity, integration of natural and social sciences to inform conservation efforts has been difficult. We examined the views of 63 scientists and practitioners involved in marine management in Mexico's Gulf of California, the central California coast, and the western Pacific on the challenges associated with integrating social science into research efforts that support ecosystem-based management (EBM) in marine systems. We used a semistructured interview format. Questions focused on how EBM was developed for these sites and how contextual factors affected its development and outcomes. Many of the traditional challenges linked with interdisciplinary research were present in the EBM projects we studied. However, a number of contextual elements affected how mandates to include social science were interpreted and implemented as well as how easily challenges could be addressed. For example, a common challenge is that conservation organizations are often dominated by natural scientists, but for some projects it was easier to address this imbalance than for others. We also found that the management and institutional histories that came before EBM in specific cases were important features of local context. Because challenges differed among cases, we believe resolving challenges to interdisciplinary research should be context specific.     

灾害化学的核心原理研究

为完善安全科学原理的内容,促进安全科学的理论发展,基于对安全科学理论体系和灾害化学的研究,提出灾害化学原理的定义及其研究内容。归纳出灾害化学的六个核心原理,即热平衡原理、过程控制原理、平衡移动原理、反应减速原理、条件阻隔原理、质能守恒原理,并分析这些原理的概念和内涵。最后,从本质化安全生产设计、职业安全健康与管理和安全经济效益的角度分析灾害化学原理的应用,并选取具体实例详细阐述了各原理的实用性。